Intel® System Studio 2014 now contains an energy and power profiler called Intel® Energy Profiler. Using the Intel Energy Profiler lets you find the software on your system that is causing unwanted power use. This article will show you how to do two collections using the Intel Energy Profiler collector, socwatch, on Android* and then use VTune Amplifier™ for Systems to compare the two collections.
Intel Energy Profiler
SoC Watch (aka SoCWatch) is a command line tool for monitoring system behaviors related to power consumption on Intel® architecture-based platforms. It monitors power states, frequencies, wakeups, and various other metrics that provide insight into the system’s energy efficiency.
Two key indicators that effect how much power your system is using are CPU Sleep states and CPU Frequency.
- CPU Sleep states (C-states)
- CPU Sleep states indicate during what intervals your CPU is asleep. The main goal of CPU Sleep states is to show when the system is sleeping, what sleep state it was in and what woke up the system. The higher the sleep state the lower the power usage.
- CPU Frequency (P-states)
- CPU’s also have the ability to change the core clock frequency, power usage will be higher the greater the frequency.
In this article we will focus on collecting C-states and P-states indicators.
To collect these indicators using socwatch run the following command.
socwatch –f cpu-cstate –f cpu-pstate –t 60 –o test
This command will collect C-states and P-states on your Android* device. It will collect for 60 seconds and store the result in filename test.sw1. After running this command you should see 2 files: test.csv and test.sw1.
Since we will be comparing two results you should run a second socwatch command and this time store the result in test1.
Copy these results back to your host machine using the adb commands:
adb pull /data/socwatch/results/test.sw1
adb pull /data/socwatch/results/test1.sw1
Comparing results using VTune Amplifier for Systems
To run the VTune Amplifier for Systems commands (on a Windows* system) in this section you will first need to execute the following batch file: C:\Program Files (x86)\Intel\System Studio 2014.0.026\VTune Amplifier 2014 for Systems\amplxe-vars.bat
In order to compare the socwatch results we have collected we first need to import them into a VTune Amplifier result directory. Use the following commands to do this:
amplxe-runss –import-socwatch-data test.sw1
amplxe-runss –import-socwatch-data test1.sw1
After running these two commands you should see two new result directories: r000, r001.
Start the VTune Amplifier for Systems gui
This will bring up the VTune Amplifier for Systems GUI.
Click on the Compare button in the tool bar:
This will bring up the following view inside of VTune Amplifier for Systems:
Fill the the view with the two results you have collected and then click Compare.
VTune Amplifier for Systems will display the differences between the two collections:
You can also clearly see the differences side-by-side using the summary histograms:
You can easily compare two different socwatch results by visualizing the data using the comparion feature in VTune Amplifier for Systems.